1 /* $NetBSD: exynos_rtc.c,v 1.4 2021/01/27 03:10:19 thorpej Exp $ */
2
3 /*-
4 * Copyright (c) 2015 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Marty Fouts
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 #include "opt_exynos.h"
33 #include "opt_arm_debug.h"
34 #include "gpio.h"
35
36 #include <sys/cdefs.h>
37 __KERNEL_RCSID(1, "$NetBSD: exynos_rtc.c,v 1.4 2021/01/27 03:10:19 thorpej Exp $");
38
39 #include <sys/param.h>
40 #include <sys/bus.h>
41 #include <sys/device.h>
42 #include <sys/intr.h>
43 #include <sys/systm.h>
44 #include <sys/kernel.h>
45 #include <sys/kmem.h>
46
47 #include <dev/clock_subr.h>
48
49 #include <arm/samsung/exynos_reg.h>
50 #include <arm/samsung/exynos_intr.h>
51
52 #include <dev/fdt/fdtvar.h>
53
54 struct exynos_rtc_softc {
55 device_t sc_dev;
56 bus_space_tag_t sc_bst;
57 bus_space_handle_t sc_bsh;
58
59 struct todr_chip_handle sc_todr;
60 };
61
62 static int exynos_rtc_match(device_t, cfdata_t, void *);
63 static void exynos_rtc_attach(device_t, device_t, void *);
64
65 static int exynos_rtc_gettime(todr_chip_handle_t, struct timeval *);
66 static int exynos_rtc_settime(todr_chip_handle_t, struct timeval *);
67
68 CFATTACH_DECL_NEW(exynos_rtc, sizeof(struct exynos_rtc_softc),
69 exynos_rtc_match, exynos_rtc_attach, NULL, NULL);
70
71 #define RTC_READ(sc, reg) \
72 bus_space_read_4((sc)->sc_bst, (sc)->sc_bsh, (reg))
73 #define RTC_WRITE(sc, reg, val) \
74 bus_space_write_4((sc)->sc_bst, (sc)->sc_bsh, (reg), (val))
75
76 static const struct device_compatible_entry compat_data[] = {
77 { .compat = "samsung,s3c6410-rtc" },
78 DEVICE_COMPAT_EOL
79 };
80
81 static int
exynos_rtc_match(device_t parent,cfdata_t cf,void * aux)82 exynos_rtc_match(device_t parent, cfdata_t cf, void *aux)
83 {
84 struct fdt_attach_args * const faa = aux;
85
86 return of_compatible_match(faa->faa_phandle, compat_data);
87 }
88
89 static void
exynos_rtc_attach(device_t parent,device_t self,void * aux)90 exynos_rtc_attach(device_t parent, device_t self, void *aux)
91 {
92 struct exynos_rtc_softc * const sc
93 = kmem_zalloc(sizeof(*sc), KM_SLEEP);
94 struct fdt_attach_args * const faa = aux;
95 bus_addr_t addr;
96 bus_size_t size;
97 int error;
98
99 if (fdtbus_get_reg(faa->faa_phandle, 0, &addr, &size) != 0) {
100 aprint_error(": couldn't get registers\n");
101 return;
102 }
103
104 aprint_normal(" @ 0x%08x", (uint)addr);
105 sc->sc_dev = self;
106 sc->sc_bst = faa->faa_bst;
107 error = bus_space_map(sc->sc_bst, addr, size, 0, &sc->sc_bsh);
108 if (error) {
109 aprint_error(": couldn't map %#" PRIxBUSADDR ": %d",
110 addr, error);
111 return;
112 }
113
114 aprint_naive("\n");
115 aprint_normal(": RTC\n");
116
117 sc->sc_todr.todr_gettime = exynos_rtc_gettime;
118 sc->sc_todr.todr_settime = exynos_rtc_settime;
119 sc->sc_todr.cookie = sc;
120 todr_attach(&sc->sc_todr);
121
122 }
123
124 static int
exynos_rtc_gettime(todr_chip_handle_t tch,struct timeval * tv)125 exynos_rtc_gettime(todr_chip_handle_t tch, struct timeval *tv)
126 {
127 struct exynos_rtc_softc * const sc = tch->cookie;
128
129 tv->tv_sec = RTC_READ(sc, EXYNOS5_RTC_OFFSET);
130 tv->tv_usec = 0;
131
132 return 0;
133 }
134
135 static int
exynos_rtc_settime(todr_chip_handle_t tch,struct timeval * tv)136 exynos_rtc_settime(todr_chip_handle_t tch, struct timeval *tv)
137 {
138 struct exynos_rtc_softc * const sc = tch->cookie;
139 int retry = 500;
140
141 while (--retry > 0) {
142 if (!RTC_READ(sc, EXYNOS5_RTC_OFFSET))
143 break;
144 delay(1);
145 }
146 if (retry == 0) {
147 device_printf(sc->sc_dev, "RTC write failed (BUSY)\n");
148 return ETIMEDOUT;
149 }
150
151 RTC_WRITE(sc, EXYNOS5_RTC_OFFSET, tv->tv_sec);
152
153 return 0;
154 }
155